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| ==Causes== | | ==Causes== |
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| [[Image:Malignant melanoma.jpg|left|thumb|240px|Nodular melanoma on the leg of an elderly woman.]]
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| Generally, an individual's risk for developing melanoma depends on two groups of factors: intrinsic and environmental.<ref>[http://www.skincarephysicians.com/skincancernet/who_is_most.html Who is Most at Risk for Melanoma?]</ref> "Intrinsic" factors are generally an individual's family history and inherited [[genotype]], while the most relevant environmental factor is sun exposure.
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| [[Epidemiologic]] studies suggest that exposure to [[ultraviolet]] radiation (UVA<ref name="uva">{{cite journal | author = Wang S, Setlow R, Berwick M, Polsky D, Marghoob A, Kopf A, Bart R | title = Ultraviolet A and melanoma: a review. | journal = J Am Acad Dermatol | volume = 44 | issue = 5 | pages = 837-46 | year = 2001 | id = PMID 11312434}}</ref> and UVB) is one of the major contributors to the development of melanoma. UV radiation causes [[DNA damage|damage]] to the [[DNA]] of cells, typically thymine dimerization, which when unrepaired can create [[mutation]]s in the cell's [[gene]]s. When the cell [[cell division|divides]], these mutations are propagated to new generations of cells. If the mutations occur in [[oncogene]]s or [[tumor suppressor gene]]s, the rate of [[mitosis]] in the mutation-bearing cells can become uncontrolled, leading to the formation of a [[tumor]]. Occasional extreme sun exposure (resulting in "[[sunburn]]") is causally related to melanoma.<ref>{{cite journal | author = Oliveria S, Saraiya M, Geller A, Heneghan M, Jorgensen C | title = Sun exposure and risk of melanoma. | journal = Arch Dis Child | volume = 91 | issue = 2 | pages = 131-8 | year = 2006 | id = PMID 16326797}}</ref> Those with more chronic long term exposure (outdoor workers) may develop protective mechanisms. Melanoma is most common on the back in men and on legs in women (areas of intermittent sun exposure) and is more common in indoor workers than outdoor workers (in a British study<ref>{{cite journal | author = Lee J, Strickland D | title = Malignant melanoma: social status and outdoor work. | journal = Br J Cancer | volume = 41 | issue = 5 | pages = 757-63 | year = 1980 | id = PMID 7426301}}</ref>). Other factors are [[mutation]]s in or total loss of [[tumor suppressor gene]]s. Use of sunbeds (with deeply penetrating UVA rays) has been linked to the development of skin cancers, including melanoma.
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| ==References== | | ==References== |
| {{Reflist|2}} | | {{Reflist|2}} |
